PHP improve my show message function - php

Question

I'd like some help please, if its possible.
I have created two functions in order to display some messages when is set a $_GET after a redirect.Here's the code:
function display(){
if(isset($_GET['cnf_upd']) && $_GET['cnf_upd'] == '1'){
$value = "The update was successful!";
$type = "confirm";
construct_the_div($value, $type);
}
if(isset($_GET['err_upd']) && $_GET['err_upd'] == '1'){
$value = "The Update failed.";
$type = "error";
construct_the_div($value, $type);
}
if(isset($_GET['cnf_del']) && $_GET['cnf_del'] == '1'){
$value = "Deleted completely.";
$type = "confirm";
construct_the_div($value, $type);
}
if(isset($_GET['err_del']) && $_GET['err_del'] == '1'){
$value = "Unable to delete.";
$type = "error";
construct_the_div($value, $type);
}
}
function construct_the_div($value, $type){
// creating a div to display the message results
$div = "<div class=\"{$type}Msg\">\n";
$div .= "<p>{$value}</p>\n";
$div .= "</div><!-- end of {$type}Msg -->\n";
echo $div;
}
What I'd like to make is to try to improve the display function, as it gets longer and longer, so that there whould be only one (or two at most) if statement(s) if possible. So the value of the GET will be dynamicly inside the if condition and also if it has the preffix 'cnf_' it wil be a 'confirmMsg' and if it has the preffix 'err_' it wil be a 'errorMsg'.
Is it possible to make something like this???

Answer 1

function display() {
$messages = array(
'cnf_upd' => 'The update was successful!',
'cnf_err' => 'The Update failed.!',
// ...
// add all error and confirm there
// ...
);
foreach($_GET as $key => $value) {
if(strpos($key, 'cnf_')===0) {
$type = 'confirm';
$value = isset($messages[$key])
? $messages[$key]
: $key;
construct_the_div($value, $type);
}
if(strpos($key, 'err_')===0) {
$type = 'error';
$value = isset($messages[$key])
? $messages[$key]
: $key;
construct_the_div($value, $type);
}
}
}

Answer 2

The approach is not correct, it seems that only one message should occur at once (there cannot be "deleted completely" and "unable to delete" at once).
Try construct the parameters this way: ?msg=upd&msgType=cnf
function display(){
if (isset($_GET['msg']) && isset($_GET['msgType']))
{
$messages = array('cnf_upd'=>'The update was successful!',
'err_upd'=>'The update failed!',
'cnf_del'=>'The deletion was successful!',
'cnf_upd'=>'The deletion failed!',
);
if (isset($messages[$_GET['msgType'].'_'.$_GET['msg']))
construct_the_div($messages[$_GET['msgType'].'_'.$_GET['msg']], htmlspecialchars($_GET['msgType']));
}
there is still much to improve, but for start this is cleaner and safer.

Answer 3

I'm going to propose a different solution. Instead of setting different parameters in $_GET based on the message to be sent, set one parameter and parse its value.
// Start by setting integer constants:
define(CNF_UPD, 1);
define(ERR_UPD, 2);
define(CNF_DEL, 3);
define(ERR_DEL, 4);
Then when you set the value un $_GET, use the constant:
// Build the URL with a deletion error...
header("Location: http://example.com/script.php?msg=" . ERR_DEL);
Finally, use a switch to parse them
if (isset($_GET['msg'])) {
switch ($_GET['msg']) {
case CNF_UPD:
// Updated...
break;
case ERR_UPD:
// failed...
break;
// etc...
default:
// invalid code.
}
}
If you use a pattern of confirm/error/confirm/error for your integer constants, you can determine which it is by taking $_GET['msg'] % 2. Odd numbers are confirmations, evens are errors. There are of course many other ways you could lay this out, I just happen to have typed them in the alternating order you used. You could also do positive integers for confirmations and negatives for errors, for example.
$type = $_GET['msg'] % 2 == 1 ? $confirm : $error;
This is easily expanded to use multiple messages as well. Since they are integer values, you can safely construct a comma-separated list and explode() them when received.
$messages = implode(array(ERR_DEL,CNF_UPD));
header("Location: http://example.com/script.php?msg=$messages");

Answer 4

Unless you can somehow generate $value and $type based on the $_GET parameter (which I can't see how you would do), you could do something like:
$messages = array();
$messages[] = array('id' => 'cnf_upd', 'value' => 'The update was successful!', 'type' => 'Confirm');
$messages[] = array('id' => 'err_upd', 'value' => 'The Update failed.', 'type' => 'error');
...
foreach ($messages as $message) {
if(isset($_GET[$message['id']]) && $_GET[$message['id']] == '1'){
construct_the_div($message['value'], $message['type']);
}
}